Operation of a personal audio device during insertion detection

ABSTRACT

A method of operating a personal audio device configured to be removed from and inserted into a user&#39;s ear can include generating an input signal by an input signal generating device. The method can also include determining whether an insertion event has occurred based on the generated input signal and causing the personal audio device to operate in a low power mode responsive to an absence of an insertion event determination after a first period of time. The method can also include causing the personal audio device to operate in an ultra-low power mode responsive to the absence of an insertion event determination after a second period of time that occurs after the first period of time, the ultra-low power mode having a lower power consumption than the low power mode.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional PatentApplication No. 62/663,521, filed Apr. 27, 2018 and entitled “HeadphoneInsertion Detection,” the disclosure of which is incorporated herein byreference in its entirety.

TECHNICAL FIELD

Embodiments of the invention are directed to methods and apparatuses fordetermining when a personal audio device has been inserted orre-inserted in or around an ear of the user and operating the headphoneduring the determining.

BACKGROUND

Typical Active Noise Cancellation (ANC) headphones are electricallypowered systems that require a battery or another power source tooperate. A commonly encountered problem with powered headphones is thatthey continue to drain the battery if the user removed the headphoneswithout turning them off. Methods and apparatus to determine when a userhas removed headphones are found in U.S. application Ser. No.15/792,394, filed Oct. 24, 2017, entitled HEADPHONE OFF-EAR DETECTION,which is assigned to the assignee of the present invention andincorporated by reference herein.

Although it is possible to configure an Off-Ear Detection (OED) system,such as a system according to the above-incorporated application, toalso detect when a user replaces their headphones in or around his orher ears (referred to here as insertion detection), there are drawbacksfrom doing so. One limitation is the amount of power consumed while theheadphones are in the off-ear state but are actively attempting todetermine when the insertion event occurs, i.e., when a user places themback on-ear. The power consumption is mostly due to having to power andenable microphone and headphone signal paths, which include microphones,preamps, Analog to Digital Converters (ADC), Digital to AnalogConverters (DAC), and headphone amps.

Embodiments according to the disclosed technology address these andother limitations.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flow diagram illustrating a first example of operations fordetecting a headphone insertion event in accordance with certainimplementations of the disclosed technology.

FIG. 2 is a flow diagram illustrating a second example of operations fordetecting a headphone insertion event in accordance with certainimplementations of the disclosed technology.

FIG. 3 is a graph illustrating exemplary changes in amplitude over timefor a signal generated by back EMF of a headphone speaker in an earbud,i.e., an in-ear headphone.

FIG. 4 is a graph illustrating exemplary changes in amplitude over timefor a signal generated by a back EMF of a headphone speaker in anaround-the-ear headphone.

FIG. 5 is a graph illustrating a signal corresponding to insertionevents and normal movements before passing through a conditioningfilter, e.g., a bandpass filter.

FIG. 6 is a graph illustrating the signal of FIG. 5 after passingthrough the conditioning filter.

FIG. 7 is a schematic block diagram illustrating an example of how atypical speaker in a headphone is operationally connected.

FIG. 8 is a schematic block diagram that illustrates an example ofmonitoring a speaker such as the speaker of FIG. 7 for back EMF toevaluate when an insertion has occurred.

FIG. 9 is a schematic block diagram that illustrates an example of apure analog mode of operation for monitoring a speaker such as thespeaker of FIG. 7.

FIG. 10 is a flow diagram illustrating an example of operating aheadphone in low power and ultra-low power modes during insertiondetection in accordance with certain embodiments of the disclosedtechnology.

FIG. 11 is a timing diagram illustrating the example of FIG. 10 in whichthe low-power detection mode can overlap either or both the full on-eardetection mode and the ultra-low power insertion detection mode inaccordance with certain embodiments of the disclosed technology.

FIG. 12 illustrates an example of a headphone, which is depicted asbeing worn by the user, or on ear in accordance with certain embodimentsof the disclosed technology.

FIG. 13 illustrates an example of a headphone, such as the headphone ofFIG. 12, which is depicted as being not worn by the user, or off ear inaccordance with certain embodiments of the disclosed technology.

FIG. 14 is a perspective view illustrating an example of a headphone,such as the headphones of FIGS. 12 and 13, in accordance with certainembodiments of the disclosed technology.

FIG. 15 illustrates an example of a pair of earbuds, which is depictedas being on ear in accordance with certain embodiments of the disclosedtechnology.

FIG. 16 illustrates an example of a pair of earbuds, such as the earbudsof FIG. 15, which is depicted as being off ear in accordance withcertain embodiments of the disclosed technology.

FIG. 17 is a perspective view illustrating an example of a pair ofearbuds, such as the earbuds of FIGS. 15 and 16, in accordance withcertain embodiments of the disclosed technology.

DETAILED DESCRIPTION

Embodiments of the disclosed technology are generally directed tomethods and apparatuses for operating one or more personal audiodevices, such as headphones or earbuds, for example, in multiple powermodes while detecting when a user puts the device(s) in or around his orher ears, referred to herein as an insertion event, by evaluating aninsertion signal generated when the user physically places the device(s)in or around either or both of his or her ears.

The personal audio device insertion signal as described herein istypically a very strong, low-frequency acoustic wave. Embodiments of thedisclosed technology are generally able to detect this insertion signalas well as differentiate the signal from other various signals. Due tothe particular techniques used as described herein, the insertion signalmay be detected using very low amounts of power.

FIG. 1 is a flow diagram illustrating a first example 100 of operationsfor detecting a personal audio device insertion event in accordance withcertain implementations of the disclosed technology. In the example 100,the flow illustrates operations used when performing the insertiondetection on a feedback signal from a feedback microphone.

ANC headphones typically include a transducer, such as a speaker orspeaker driver, for producing sound, a feedback microphone for samplingsounds within the ear or ear cup, and a feedforward microphone forsampling sounds outside the ear or ear cup. Embodiments of the disclosedtechnology generally include monitoring a signal generated by either orboth the transducer and the feedback microphone to determine whether aninsertion event occurred. FIG. 1 illustrates operations used by thesystem when evaluating a signal generated by the feedback microphone.

In the example 100, a signal is received from the feedback microphone ina first operation 110. Although a signal from the feedforward microphonecould also be monitored, monitoring the feedback microphone is oftenpreferred because such monitoring generally produces a stronger signalwhen the headphone is inserted in or on the ear of the user than doesthe feedforward microphone.

The signal from the feedback microphone is typically filtered in asecond operation 120, by passing the signal from the feedback microphonethrough a conditioning filter such as a bandpass filter or a lowfrequency filter, for example. Which conditioning filter is used by asystem may be implementation specific.

In certain embodiments, a template matching operation 130 may performed.Such template matching may include determining whether the filteredsignal remains above a threshold for a certain period of time. In acomparing operation 140, the filtered signal is compared to a signallevel threshold. The threshold in operation 140 may be the samethreshold or a different threshold that that used during operation 130.

An operation 150 determines whether the filtered signal has exceeded thethreshold used in operation 140. If the determination is that the signalhas exceeded the threshold, then the system creates an insertiondetection signal as indicated by operation 160. Conversely, if thedetermination is that the signal did not exceed the threshold, then noinsertion detection signal is generated as indicated by operation 170.

The operations illustrated by FIG. 1 may be used by a headphone whilethe headphone is operating in a low power mode.

If the insertion detection signal is generated, the signal may be usedto initiate various events, such as automatically turning on music thatwas previously paused after an off-ear detection signal was generated.If instead no insertion detection signal is generated, the flow 100 mayrepeat until such an insertion detection occurs.

FIG. 2 is a flow diagram illustrating a second example 200 of operationsfor detecting a headphone insertion event in accordance with certainimplementations of the disclosed technology. In the example 200, theflow includes operations for monitoring a signal generated by atransducer of the headphone, such as a speaker or speaker driver, whichis also referred to herein as receiving the signal from the headphone.

A microphone, such as the feedback microphone referred to by FIG. 1,typically generates an electrical signal by converting an acousticsignal, such as from a voice, to an electrical signal. A transducer,e.g., a moving coil transducer or an audio speaker, typically generatesan acoustic signal by passing a modulating electrical signal through aspeaker driver coil, which in turn moves the transducer to generate theacoustic signal. A transducer can also work in reverse, by generating anelectrical signal in response to being perturbed by an external acousticsignal, for example.

The electrical signal generated by exposing the transducer to acousticpower may be referred to as back Electro-Motive Force, or back EMF.Certain implementations of the disclosed technology may take advantageof this by monitoring a signal generated by the transducer of aheadphone, such as when the user places the headphone in or around hisor her ear. In certain implementations, the transducer converts sensedpressure to an output signal.

Operation of the flow in the example 200 are generally similar to theoperation of the flow in the example 100 of FIG. 1, except that thesignal generated by the headphone, e.g., the transducer, is differentthan the signal generated by the feedback microphone. Specifically,operating the transducer in reverse is generally not as sensitive of amicrophone as an actual feedback microphone, but this difference can beovercome by using slightly different steps to determine insertiondetection. In the example 200, a signal is received by monitoring theback EMF of the headphone in a first operation 210. An optional secondoperation 220 includes filtering the back EMF signal, as the naturalqualities of the back EMF generally lend themselves to easier detectionthan the signal from the feedback microphone.

In certain embodiments, a template matching operation 230 may performed.Such template matching may include determining whether the filteredsignal remains above a threshold for a certain period of time. In acomparing operation 240, the filtered signal is compared to a signallevel threshold. The threshold in operation 240 may be the samethreshold or a different threshold that that used during operation 230.

An operation 250 determines whether the filtered signal has exceeded thethreshold used in operation 240. If the determination is that the signalhas exceeded the threshold, then the system creates an insertiondetection signal as indicated by operation 260. Conversely, if thedetermination is that the signal did not exceed the threshold, then noinsertion detection signal is generated as indicated by operation 270.

The operations illustrated by FIG. 2 may be used by a headphone whilethe headphone is operating in an ultra-low power mode, because thesystem uses less power in detecting the back EMF signal from theheadphone speaker rather than being forced to power the feedbackmicrophone, as was the case for the operations described with referenceto FIG. 1.

FIG. 3 is a graph 300 illustrating exemplary changes in amplitude overtime for a signal generated by back EMF of a headphone speaker in anearbud, i.e., an in-ear headphone. In the example 300, the insertionevents have a significantly higher amplitude than that of the normalmovements.

FIG. 4 is a graph 400 illustrating exemplary changes in amplitude overtime for a signal generated by a back EMF of a headphone speaker in anaround-the-ear headphone. In the example 400, there is a cleardifference between the amplitudes of the insertion events and thebackground noise, though not as pronounced as in the in-ear headphoneexample 300 illustrated by FIG. 3.

FIG. 5 is a graph 500 illustrating a signal corresponding to insertionevents and normal movements before passing through a conditioningfilter, e.g., a bandpass filter, and FIG. 6 is a graph 600 illustratingthe signal of FIG. 5 after being passed through the conditioning filter.In comparing the graphs 500 and 600, one can readily appreciate that thefiltered signal makes it much easier to differentiate the insertionevents from the background noise based on their increased signal tonoise ratio.

FIG. 7 is a schematic block diagram illustrating an example 700 of how atypical transducer 730, e.g., a speaker or speaker driver, in aheadphone is operationally connected. In the example 700, an analogsignal is generated by a Digital to Analog Converter (DAC) 710. Theanalog signal is then amplified by a power amplifier 720 and passed tothe transducer 730 to generate the intended sounds for the user.

FIG. 8 is a schematic block diagram that illustrates an example 800 ofmonitoring a transducer 830, e.g., a speaker or speaker driver, such asthe transducer 730 of FIG. 7, for back EMF to evaluate when an insertionevent has occurred. In this low-power mode, an amplifier 820, such asthe amplifier 720 of FIG. 7, is powered down or completely powered offand the transducer 830 is coupled with an Analog to Digital Converter(ADC) 840 such that, when the transducer 830 is exposed to acousticenergy, the transducer 830 may generate an electrical signal that passesthrough the ADC and can be monitored. Optionally, the electrical signalmay be passed through a conditioning filter such as a bandpass filter.

FIG. 9 is a schematic block diagram that illustrates an example 900 of apure analog mode of operation for monitoring a transducer 930, such asthe transducer 730 of FIG. 7. In this ultra-low power mode in which theamplifier 920 is powered down or off as well as the microphone (notshown), the back EMF signal is directly compared to an analog thresholdsignal through a comparator 940. When the comparator 940 indicates theback EMF is above the threshold, an insertion detection signal may begenerated. Otherwise, no insertion detection signal occurs. Optionally,the signal from the comparator 940 may be passed through a conditioningfilter such as a bandpass filter.

FIG. 10 is a flow diagram illustrating an example 1000 of operating apersonal audio device, such as a headphone or earbud, for example, inregular power, low power, and ultra-low power modes during insertiondetection in accordance with certain embodiments of the disclosedtechnology. At an initial operation 1002, the headphone is operating ina normal power mode, e.g., playing music for a user, and the off-eardetection (OED) is full on, meaning that a microphone and transducer,e.g., a speaker, are both being used for detecting a headphone insertionevent. In an optional operation at 1004, either or both of the signalsfrom the microphone and transducer are passed through a conditioningfilter, such as a bandpass filter or a low-pass filter. Operation 1004may be triggered the headphones have been removed for a certain periodof time, e.g., between 1-20 seconds.

At operation 1006, the headphone enters a low-power mode by way ofsignificantly reducing or completely removing the operating power of theamplifier, leaving only the microphone for performing the insertiondetection. In certain implementations, the low power mode isaccomplished by increasing the impedance of the power amplifier suchthat it exceeds the impedance of the transducer.

Responsive to the detection of an insertion event, power may be restoredto the amplifier as indicated by operation 1008. Once the amplifierreturns to normal power, as indicated by 1010, the headphone may returnto full on OED, as indicated by 1002, and the headphone may resumeplaying music that had been previously paused after the headphone hadbeen removed from the user's ear, for example.

After the operating power to the amplifier has been reduced at 1006 anda certain period of time has passed for the amplifier to be powereddown, as indicated by 1012, the signal from the microphone may beoptionally passed through a conditioning filter, such as a bandpassfilter or low-pass filter, as indicated by 1014.

At operation 1016, the headphone enters an ultra-low power mode by wayof significantly reducing or completely removing the operating power tothe microphone, leaving only the transducer, without power from theamplifier, for performing the headphone insertion detection. Responsiveto the detection of an insertion event, power may be restored to eitheror both the amplifier and the microphone as indicated by operation 1018.Once the amplifier returns to normal power, as indicated by 1010, theheadphone may return to full on OED, as indicated by 1002, and theheadphone may resume playing music that had been previously paused afterthe headphone had been removed from the user's ear, for example.

It will be appreciated that it is generally beneficial for the headphoneto operate the insertion detection in the low power mode before movingdirectly to the ultra-low power mode because it takes relatively longerfor the system to enter the ultra-low power mode. So, it is possiblethat an insertion event may be missed and therefore not detected whilethe system is changing from the regular operating mode to the ultra-lowpower mode. By changing to the low power mode before entering theultra-power mode, such insertion events will not be missed because thesystem always has at least one insertion detection mode in operation.Operating in these modes is possible because it is possible for thesystem to operate in the low power mode and the ultra-low power modesimultaneously as well as to operate in the low power mode and theregular operating mode simultaneously.

If, however, no insertion is detected while in the low power mode, thesystem enters the ultra-low power mode by first turning off the driveramplifier. After the amplifier is turned off, the system beginsmonitoring the back EMF of the speaker of the headphone in the ultra lowpower mode as described above. When the system detects an insertionwhile in the ultra low power mode, both the microphones and amplifiersare turned on. After the microphones and amplifiers are turned on, thesystem returns to its initial ON state, and music again begins to playfor the user.

FIG. 11 is a timing diagram 1100 illustrating the example 1000 of FIG.10 in which the low-power detection mode of the personal audio devicecan overlap either or both the full off-ear detection mode and theultra-low power insertion detection mode in accordance with certainembodiments of the disclosed technology.

An initial operation 1102, the personal audio device, such as aheadphone or earbud, for example, is operating in a normal power mode,e.g., playing music for a user, and the off-ear detection (OED) is fullon, meaning that a microphone and transducer, e.g., a speaker, are bothbeing used for detecting a headphone insertion event. In an optionaloperation at 1104, either or both of the signals from the microphone andthe transducer may be passed through a conditioning filter, such as abandpass filter or a low-pass filter. Operation 1104 may be triggeredthe headphones have been removed from the user's ear for a certainperiod of time, e.g., between 1-20 seconds.

At operation 1106, the headphone enters a low-power mode by way ofsignificantly reducing or completely removing the operating power of theamplifier for the transducer, as indicated by operation 1107, thusleaving only the microphone for performing the headphone insertiondetection. In certain implementations, the low power mode may beaccomplished by increasing the impedance of the power amplifier suchthat it exceeds the impedance of the transducer.

After the operating power to the amplifier has been reduced or removedat 1106 and a certain period of time has passed for the amplifier to bepowered down, as indicated by 1112, the signal from the microphone maybe optionally passed through a conditioning filter, such as a bandpassfilter or low-pass filter, as indicated by 1114. In certain embodiments,waiting for the amplifier to power down at operation 1112 may includewaiting for an impedance of the amplifier to go to a high impedance. Thewaiting period at 1112 may also include waiting for the conditioningfilter to settle.

At operation 1116, the headphone enters an ultra-low power mode by wayof significantly reducing or completely removing the operating power tothe microphone, as indicated by operation 1117, leaving only thetransducer, without power from the amplifier, for performing theheadphone insertion detection.

It will be appreciated that, because the different insertion detectionmodes can operate simultaneously, the overall system can work in anyoperating power mode, and during any transition to any other operationpower mode, without experiencing periods where the system is unable todetect headphone insertion events.

FIG. 12 illustrates an example 1200 of a headphone 1202, which isdepicted as being worn, or on ear, in accordance with certainembodiments of the disclosed technology. In the example, portions of orall of a headphone insertion detection system 1204 as described hereinis integrated with the headphone 1202.

FIG. 13 illustrates an example 1300 of a headphone 1302, such as theheadphone 1202 of FIG. 12, having integrated therewith a headphoneinsertion detection system 1304, such as the headphone insertiondetection system 1204 of FIG. 12. In the example 1300, the headphone1300 is depicted as being not worn, or off ear, in accordance withcertain embodiments of the disclosed technology.

FIG. 14 is a perspective view 1400 illustrating an example of aheadphone 1402, such as the headphones 1202 and 1302 of FIGS. 12 and 13,respectively, in accordance with certain embodiments of the disclosedtechnology. It will be appreciated that, as used herein, the termheadphone may be used to describe virtually any type of headphones thatgenerally include one or more cup portions that each have a speaker orother suitable transducer configured to provide an audio output to auser.

A headphone as described herein is typically arranged to be worn suchthat each cup—and thus corresponding speaker—is on, around, or otherwisein close proximity to one of the user's ears, e.g., when the userdesires to listen to music or other audio content. The headphone alsogenerally includes a band or other mechanism configured to rest on topof or around the user's head so as to effectively maintain positioningof the speakers on, around, or otherwise in close proximity to theuser's ears, e.g., so that the user may listen to music or other audiooutput provided from either one or both of the speakers. The headphonemay be circumaural or supra-aural, for example. The headphone may bewired or wireless.

In certain implementations, a headphone can include a headphoneinsertion detection system, such as the headphone insertion detectionsystem 1204 and 1304 of FIGS. 12 and 13, respectively. The detectionsystem may include a microphone that is configured to convert an ambientsound wave to an electrical audio signal and one or more filtersconfigured to receive the electrical audio signal from the microphoneand produce a modified audio signal based on certain filter parameters.

The detection system may also include a transducer configured to converta sensed pressure to a second electrical audio signal and a secondaryfilter configured to receive the electrical audio signal from themicrophone and produce a modified audio signal based on certain filterparameters. The system may include a control circuit configured todetermine whether either or both of the modified audio signals exceeds arespectively corresponding signal level threshold as described elsewhereherein.

FIG. 15 illustrates an example 1500 of a pair of earbuds 1502 and 1503,which is depicted as being worn, or in ear in accordance with certainembodiments of the disclosed technology. In the example, portions of orall of an earbud insertion detection system as described herein isintegrated with the earbuds 1502 and 1503.

FIG. 16 illustrates an example 1600 of a pair of earbuds 1602 and 1603,such as the earbuds 1502 and 1503 of FIG. 15, having integratedtherewith an earbud insertion detection system. In the example 1600, thepair of earbuds 1602 and 1603 is depicted as being not worn, or out ear,in accordance with certain embodiments of the disclosed technology.

FIG. 17 is a perspective view 1700 illustrating an example of a pair ofearbuds 1702 and 1703, such as the earbuds 1502-1503 and 1602-163 ofFIGS. 15 and 16, respectively, in accordance with certain embodiments ofthe disclosed technology. It will be appreciated that, as used herein,the term earbud may be used to describe virtually any type of individualelectronic device having a casing or other suitable portion that isconfigured to house or otherwise support a speaker or other suitabletransducer integrated therewith and configured to provide an audiooutput to a user. The earbud is typically arranged to be worn in or inclose proximity to a user's ear canal and may optionally be circumauralor supra-aural, for example. The earbud may be wired or wireless.

In certain implementations, an earbud as described herein can include anearbud insertion detection system. The detection system may include amicrophone that is configured to convert an ambient sound wave to anelectrical audio signal and one or more filters configured to receivethe electrical audio signal from the microphone and produce a modifiedaudio signal based on certain filter parameters.

The detection system may also include a transducer configured to converta sensed pressure to a second electrical audio signal and a secondaryfilter configured to receive the electrical audio signal from themicrophone and produce a modified audio signal based on certain filterparameters. The system may include a control circuit configured todetermine whether either or both of the modified audio signals exceeds arespectively corresponding signal level threshold as described elsewhereherein.

The disclosed aspects may be implemented, in some cases, in hardware,firmware, software, or any combination thereof. The disclosed aspectsmay also be implemented as instructions carried by or stored on one ormore or non-transitory computer-readable media, which may be read andexecuted by one or more processors. Such instructions may be referred toas a computer program product. Computer-readable media, as discussedherein, means any media that can be accessed by a computing device. Byway of example, and not limitation, computer-readable media may comprisecomputer storage media and communication media.

Additionally, this written description makes reference to particularfeatures. It is to be understood that the disclosure in thisspecification includes all possible combinations of those particularfeatures. For example, where a particular feature is disclosed in thecontext of a particular aspect, that feature can also be used, to theextent possible, in the context of other aspects.

Also, when reference is made in this application to a method having twoor more defined steps or operations, the defined steps or operations canbe carried out in any order or simultaneously, unless the contextexcludes those possibilities.

Furthermore, the term “comprises” and its grammatical equivalents areused in this disclosure to mean that other components, features, steps,processes, operations, etc. are optionally present. For example, anarticle “comprising” or “which comprises” components A, B, and C cancontain only components A, B, and C, or it can contain components A, B,and C along with one or more other components.

Also, directions such as “right” and “left” are used for convenience andin reference to the diagrams provided in figures. But the disclosedsubject matter may have a number of orientations in actual use or indifferent implementations. Thus, a feature that is vertical, horizontal,to the right, or to the left in the figures may not have that sameorientation or direction in all implementations.

EXAMPLES

Illustrative examples of the technologies disclosed herein are providedbelow. An embodiment of the technologies may include any one or more,and any combination of, the examples described below.

Example 1 includes a method for operating a personal audio deviceconfigured to be removed from and inserted into a user's ear, the methodcomprising: generating an input signal by each of a plurality of inputsignal generating devices of the personal audio device; determiningwhether an insertion event has occurred based on each generated inputsignal; causing the personal audio device to operate in a low power moderesponsive to an absence of an insertion event determination after afirst period of time; and causing the personal audio device to operatein an ultra-low power mode responsive to the absence of an insertionevent determination after a second period of time that occurs after thefirst period of time, the ultra-low power mode having a lower powerconsumption that the low power mode.

The personal audio device of Example 1 may include a headphone or anearbud, for example.

Example 2 includes the method of Example 1, the method furthercomprising causing the personal audio device to operate in a regularpower mode responsive to a determination that an insertion event hasoccurred.

Example 3 includes the method of any of Examples 1-2 wherein causing thepersonal audio device to operate in a low power mode includes reducingpower to a power amplifier coupled with a first one of the plurality ofinput signal generating devices.

Example 4 includes the method of Example 3 wherein the first one of theplurality of input signal generating devices is a transducer.

Example 5 includes the method of Example 3 wherein causing the personalaudio device to operate in an ultra-low power mode includes reducingpower to a second one of the plurality of input signal generatingdevices.

Example 6 includes the method of Example 5 wherein the second one of theplurality of input signal generating devices is a microphone.

Example 7 includes the method of Example 4, the method furthercomprising triggering the second period of time once an impedance of thepower amplifier exceeds an impedance of the transducer.

Example 8 includes the method of Example 4, the method furthercomprising the transducer converting a sensed pressure into the inputsignal generated by the transducer.

Example 9 includes the method of Example 6, the method furthercomprising the microphone converting an ambient sound wave into theinput signal generated by the microphone.

Example 10 includes the method of any of Examples 1-9, the methodfurther comprising filtering each input signal.

Example 11 includes an insertion detection system for detectinginsertion of a personal audio device into a user's ear comprising: amicrophone configured to convert an ambient sound wave to a firstelectrical audio signal; a first filter configured to receive the firstelectrical audio signal from the microphone and produce a first modifiedaudio signal based on first filter parameters; a transducer configuredto convert a sensed pressure to a second electrical audio signal; asecond filter configured to receive the second electrical audio signalfrom the microphone and produce a second modified audio signal based onsecond filter parameters; and a control circuit configured to determinewhether either or both of the first and second modified audio signalsexceeds a respectively corresponding signal level threshold.

The personal audio device of Example 11 may include a headphone or anearbud, for example.

Example 12 includes the system of Example 11 wherein each of the firstand second filters is a bandpass filter or a low frequency filter.

Example 13 includes the system of any of Examples 11-12 wherein thecontrol circuit is further configured to generate an insertion detectionsignal responsive to a determination that either or both of the firstand second modified audio signals exceeds the respectively correspondingsignal level threshold.

Example 14 includes the system of Example 13 further comprising aspeaker configured to, responsive to the generated insertion detectionsignal, resume playing an audio output that had been paused responsiveto a removal of the headphone from the user's ear.

Example 15 includes the system of any of Examples 11-14 furthercomprising an amplifier coupled with the transducer and configured to bepowered down responsive to neither of the first and second modifiedaudio signals exceeding the respectively corresponding signal levelthreshold after a first period of time.

Example 16 includes the system of Example 15 wherein the microphone isfurther configured to be powered down responsive to neither of the firstand second modified audio signals exceeding the respectivelycorresponding signal level threshold after a second period of time thatoccurs after the first period of time.

Example 17 includes a system for detecting insertion of a personal audiodevice into a user's ear comprising: a speaker driver configured togenerate an input signal based on a sensed pressure; and a controlcomponent configured to determine whether the input signal exceeds asignal level threshold and create an insertion detection signalresponsive to a determination that the input signal exceeds the signallevel threshold.

The personal audio device of Example 17 may include a headphone or anearbud, for example.

Example 18 includes the system of Example 17 wherein the controlcomponent includes a conditioning filter mechanism configured to filterthe input signal before determining whether the input signal exceeds thesignal level threshold.

Example 19 includes the system of any of Examples 17-18 wherein thecontrol component includes a comparator configured to compare the inputsignal to the signal level threshold.

Example 20 includes the system of any of Examples 17-19 furthercomprising an amplifier coupled with the transducer and configured to bepowered down after a removal of the headphone from the user's ear.

Having described and illustrated the principles of the invention withreference to illustrated embodiments, it will be recognized that theillustrated embodiments may be modified in arrangement and detailwithout departing from such principles, and may be combined in anydesired manner. And although the foregoing discussion has focused onparticular embodiments, other configurations are contemplated.

In particular, even though expressions such as “according to anembodiment of the invention” or the like are used herein, these phrasesare meant to generally reference embodiment possibilities, and are notintended to limit the invention to particular embodiment configurations.As used herein, these terms may reference the same or differentembodiments that are combinable into other embodiments.

Although specific embodiments of the invention have been illustrated anddescribed for purposes of illustration, it will be understood thatvarious modifications may be made without departing from the spirit andscope of the invention. Accordingly, the invention should not be limitedexcept as by the appended claims.

1. A method for operating a personal audio device configured to beremoved from and inserted into a user's ear, the method comprising:generating an input signal by each of a plurality of input signalgenerating devices of the personal audio device; determining whether aninsertion event has occurred based on each generated input signal;causing the personal audio device to operate in a low power moderesponsive to an absence of an insertion event determination after afirst period of time; and causing the personal audio device to operatein an ultra-low power mode responsive to the absence of an insertionevent determination after a second period of time that occurs after thefirst period of time, the ultra-low power mode having a lower powerconsumption than the low power mode.
 2. The method of claim 1 furthercomprising causing the personal audio device to operate in a regularpower mode responsive to a determination that an insertion event hasoccurred.
 3. The method of claim 1 wherein causing the personal audiodevice to operate in a low power mode includes reducing operating powerto a power amplifier coupled with a first one of the plurality of inputsignal generating devices.
 4. The method of claim 3 wherein the firstone of the plurality of input signal generating devices is a transducer.5. The method of claim 3 wherein causing the personal audio device tooperate in an ultra-low power mode includes reducing operating power toa second one of the plurality of input signal generating devices.
 6. Themethod of claim 5 wherein the second one of the plurality of inputsignal generating devices is a microphone.
 7. The method of claim 4further comprising triggering the second period of time once animpedance of the power amplifier exceeds an impedance of the transducer.8. The method of claim 4 further comprising the transducer converting asensed pressure into the input signal generated by the transducer. 9.The method of claim 6 further comprising the microphone converting anambient sound wave into the input signal generated by the microphone.10. The method of claim 1 further comprising filtering each inputsignal.
 11. A personal audio device insertion detection system fordetecting insertion of a personal audio device into a user's ear,comprising: a microphone configured to convert an ambient sound wave toa first electrical audio signal; a first filter configured to receivethe first electrical audio signal from the microphone and produce afirst modified audio signal based on first filter parameters; atransducer configured to convert a sensed pressure to a secondelectrical audio signal; a second filter configured to receive thesecond electrical audio signal from the microphone and produce a secondmodified audio signal based on second filter parameters; and a controlcircuit configured to determine whether either or both of the first andsecond modified audio signals exceeds a respectively correspondingsignal level threshold.
 12. The personal audio device insertiondetection system of claim 11 wherein each of the first and secondfilters is a bandpass filter or a low frequency filter.
 13. The personalaudio device insertion detection system of claim 11 wherein the controlcircuit is further configured to generate an insertion detection signalresponsive to a determination that either or both of the first andsecond modified audio signals exceeds the respectively correspondingsignal level threshold.
 14. The personal audio device insertiondetection system of claim 13 further comprising a speaker configured to,responsive to the generated insertion detection signal, resume playingan audio output that had been paused responsive to a removal of theheadphone from the user's ear.
 15. The personal audio device insertiondetection system of claim 11 further comprising an amplifier coupledwith the transducer and configured to be powered down responsive toneither of the first and second modified audio signals exceeding therespectively corresponding signal level threshold after a first periodof time.
 16. The personal audio device insertion detection system ofclaim 15 wherein the microphone is further configured to be powered downresponsive to neither of the first and second modified audio signalsexceeding the respectively corresponding signal level threshold after asecond period of time that occurs after the first period of time.
 17. Asystem for detecting insertion of a personal audio device into a user'sear, comprising: a speaker driver configured to generate an input signalbased on a sensed pressure; and a control component configured todetermine whether the input signal exceeds a signal level threshold andcreate an insertion detection signal responsive to a determination thatthe input signal exceeds the signal level threshold.
 18. The system ofclaim 17 wherein the control component includes a conditioning filtermechanism configured to filter the input signal before determiningwhether the input signal exceeds the signal level threshold.
 19. Thesystem of claim 17 wherein the control component includes a comparatorconfigured to compare the input signal to the signal level threshold.20. The system of claim 17 further comprising a power amplifier coupledwith and configured to provide power to the transducer and be powereddown after a removal of the headphone from the user's ear.